Golf club head

ABSTRACT

A golf club head has a striking face with a plurality of scorelines including a first scoreline and a second scoreline adjacent thereto. The striking face also has a plurality of auxiliary grooves each spaced from the scorelines. In a first imaginary vertical plane, a first path is formed by a first intersection between the first imaginary vertical plane and the striking face, and the auxiliary grooves have a first concentration no less than 0.17 measured between the first and second scorelines. A second imaginary vertical plane is horizontally spaced from the first imaginary plane. A second path is formed in the second imaginary vertical plane by a second intersection between the second imaginary vertical plane and the striking face. The auxiliary grooves in the second imaginary vertical plane have a second concentration that is different from the first concentration measured between the first and second scorelines.

COPYRIGHT AUTHORIZATION

The disclosure below may be subject to copyright protection. Thecopyright owner has no objection to the facsimile reproduction by anyoneof the documents contained in this disclosure as they appear in thePatent and Trademark Office records, but otherwise reserves allapplicable copyrights.

BACKGROUND OF THE INVENTION

A common desire in golf club manufacturing is to produce a club headhaving a striking face that imparts significant spin on a hit ball.Specifically, iron-type and utility-type golf club heads generallyinclude a striking face having a plurality of grooves, or scorelinesthereon. Such scorelines assist in imparting spin to a golf ball atleast by channeling water and debris and improving traction between thestriking face and the golf ball. However, the ability of scorelines toincrease spin on a hit golf ball is limited in part by USGA regulationgoverning scoreline geometry. In addition, conventional scorelines failto account for low-scale dynamic interaction characteristics between thestriking face and the golf ball.

To further improve the ability of the striking face to impart spin,conventional club heads have included low-scale surface textures inaddition to, or in place of, scorelines. However, such surface texturestend not to be tailored to the specific interaction between anelastomeric-coated golf ball and a metallic striking face. Further,conventional surface texturing is subject to rapid wear and costly toproduce.

Also, common striking face surface textures are generally ineffective atenabling high spin for each of a variety of golf shot types that agolfer may attempt. For example, a golf ball hit by a golfer using aconventional club head with a specified swing speed would generally havea reduced ball spin if the golfer were to attempt a shot with the clubface open, i.e. a “flop shot,” as compared with a typical golf shot withthe club head squarely addressed.

SUMMARY

Certain embodiments of the present invention, in one or more aspectsthereof, may advantageously comprise a golf club head that deliversimproved spin production, increased player confidence, and increasedplayability of the golf club.

According to various embodiments, a golf club head comprises a strikingface having: a plurality of scorelines including a first scoreline and asecond scoreline adjacent to the first scoreline, and a plurality ofauxiliary grooves each spaced from the plurality of scorelines. When theclub head is in a reference position, in a first imaginary verticalplane generally perpendicular to the striking face and passing throughthe first and second scorelines, a first path is formed by a firstintersection between the first imaginary vertical plane and the strikingface. The plurality of auxiliary grooves has a first concentration noless than 0.17 measured between the first scoreline and the secondscoreline. In a second imaginary vertical plane generally perpendicularto the striking face and passing through the first and secondscorelines, the second imaginary vertical plane being horizontallyspaced from the first imaginary plane, a second path is formed by asecond intersection between the second imaginary vertical plane and thestriking face, and the plurality of auxiliary grooves has a secondconcentration measured between the first scoreline and the secondscoreline. The second concentration is different from the firstconcentration.

According to various embodiments, a golf club head, when oriented in areference position, comprises a top portion, and a bottom portionopposite the top portion, a heel portion, and a toe portion opposite theheel portion, a hosel extending from the heel portion, and a strikingface. The striking face has a plurality of scorelines including a firstscoreline and a second scoreline adjacent to the first scoreline, and aplurality of texture elements, each spaced from the plurality ofscorelines. A first and a second imaginary vertical plane, eachgenerally perpendicular to the striking face, and each passing throughthe first and the second scorelines, are horizontally spaced from eachother by 10 mm. A third and a fourth imaginary vertical plane, eachgenerally perpendicular to the striking face, and each passing throughthe first and the second scorelines, are each located toeward of boththe first and the second imaginary vertical planes, and are horizontallyspaced from each other by 10 mm. A first region is delimited by thefirst imaginary plane and the second imaginary plane, and, in the firstregion, the plurality of texture elements has an average concentration,C₁, measured between the first and the second scorelines. A secondregion is delimited by the third imaginary plane and the fourthimaginary plane, and, in the second region, the plurality of textureelements has an average concentration, C₂, measured between the firstand the second scorelines. A ratio, C₂/C₁ is no greater than 0.85.

According to various embodiments, a golf club head when oriented in areference position relative to a ground plane comprises a heel portionand a toe portion opposite the heel portion, a hosel extending from theheel portion, and a striking face. The striking face has a striking faceplane, a face center, a central region including the face center, aperipheral region outward of the central region, and a plurality ofscorelines that include at least a first scoreline and a secondscoreline adjacent the first scoreline. The plurality of scorelinesextending into the central region and the peripheral region. Thestriking face also has a plurality of auxiliary grooves at leastpartially interspersed within the plurality of scorelines. The pluralityof auxiliary grooves extends into the central region and the peripheralregion. In the central region, one or more of the plurality of auxiliarygrooves follows a generally horizontal path relative to the groundplane, and the plurality of auxiliary grooves have an averageconcentration no less than 0.17 between the first scoreline and thesecond scoreline. In the peripheral region, one or more of the pluralityof auxiliary grooves follows a non-horizontal path relative to theground plane.

According to various embodiments, a golf club head, when oriented in areference position relative to a ground plane, comprises a heel portionand a toe portion opposite the heel portion, a hosel extending from theheel portion, and a striking face. The striking face has a striking faceplane, a plurality of scorelines having a heelwardmost extent, atoewardmost extent, and a width, W, being the horizontal distancebetween the heelwardmost extent and the toewardmost extent. Theplurality of scorelines includes at least a first scoreline and a secondscoreline adjacent the first scoreline. A plurality of auxiliary groovesis at least partially interspersed within the plurality of scorelines. Afirst imaginary vertical plane, perpendicular to the striking faceplane, passes through the heelwardmost extent of the plurality ofscorelines. A second imaginary vertical plane, parallel to the firstimaginary vertical plane, passes through the toewardmost extent of theplurality of scorelines. A third imaginary vertical plane is parallel tothe first imaginary vertical plane and equidistant between the firstimaginary vertical plane and the second imaginary vertical plane. Afourth imaginary vertical plane is parallel to the first imaginaryvertical plane and spaced from the third imaginary vertical plane towardthe heelwardmost extent by a distance, D, that is between 0.10*W and0.45*W. A fifth imaginary vertical plane is parallel to the firstimaginary vertical plane and spaced from the third imaginary verticalplane toward the toewardmost extent by the distance D. A central regionis delimited by the fourth and the fifth imaginary vertical planes. Aheel region is delimited by the first and the fourth imaginary verticalplanes. A toe region is delimited by the second and the fifth imaginaryvertical planes. In the central region, one or more of the plurality ofauxiliary grooves follows a generally horizontal path relative to theground plane and the plurality of auxiliary grooves have a concentrationno less than 0.17 measured between the first scoreline and the secondscoreline. Further, in at least one of the heel region and the toeregion, one or more of the plurality of auxiliary grooves follows anon-horizontal path relative to the ground plane.

These and other features and advantages of the golf club head accordingto the invention in its various aspects, as provided by one or more ofthe various examples described in detail below, will become apparentafter consideration of the ensuing description, the accompanyingdrawings, and the appended claims. The accompanying drawings are forillustrative purposes only and are not intended to limit the scope ofthe present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention, in one or more aspects thereof, is illustrated byway of example and not by way of limitation, in the figures of theaccompanying drawings, where:

FIG. 1 is a front elevation view of a golf club head according tovarious embodiments;

FIG. 1( a) is a toe-side elevation view thereof;

FIG. 2 is a front elevation view of the golf club head of FIG. 1 showingfurther detail;

FIG. 2( a)(1) is a toe-side cross-sectional view in an imaginary planeA-A′ of FIG. 2;

FIG. 2( a)(2) is a toe-side enhanced cross-sectional view in theimaginary plane A-A′ of FIG. 2;

FIG. 2( b)(1) is a toe-side cross-sectional view in an imaginary planeB-B′ of FIG. 2;

FIG. 2( b)(2) is a toe-side enhanced cross-sectional view in theimaginary plane B-B′ of FIG. 2;

FIG. 3 is a view of a golf club head according to FIG. 2 with a strikingface plane in the plane of the paper;

FIG. 3( a) is a detail view of a portion of the golf club head of FIG.3;

FIG. 3( b) is a detail view of a portion of the golf club head of FIG.3( a);

FIG. 3( b)(1) is a toe-side cross-sectional view in an imaginary placeC-C′ of FIG. 3( b);

FIG. 3( c) is a detail view of a portion of the golf club head of FIG.3( a);

FIG. 3( c)(1) is a toe-side cross-sectional view in an imaginary planeD-D′ of FIG. 3( c);

FIG. 4 is a front view of the golf club head of FIG. 3 with a strikingface plane in the plane of the paper; and

FIG. 5 is a front view of a golf club according to various embodimentswith a striking face plane in the plane of the paper.

For purposes of illustration, these figures are not necessarily drawn toscale. In all the figures, same or similar elements are designated bythe same reference numerals.

DETAILED DESCRIPTION

Representative examples of one or more novel and nonobvious aspects andfeatures of the golf club head according to the present invention,disclosed below, are not intended to be limiting in any manner.Furthermore, the various aspects and features of the present inventionmay be used alone or in a variety of novel and nonobvious combinationsand subcombinations with one another.

Iron-type and utility-type golf club heads generally include a strikingface that interfaces with and strikes a golf ball. A plurality ofgrooves, or scorelines, is provided on the striking face to assist inimparting spin to the golf ball. A portion of the face may have an areawith a different type of surface treatment that extends beyond thescoreline extents. Conventionally, the orientation of the scorelines issuch that spin is maximized when the striking face squarely impacts thegolf ball with respect to a target line. However, when the orientationof the striking face deviates from the target line, e.g. when a golferattempts a “flop shot” by opening the face of the club head, spinproduction and playability are reduced.

The striking face is selectively textured to enhance playability. Theface point of contact with the ball, as well as the orientation andlocation of a contact path, varies depending upon the particular golfshot being performed. If the ball is laying on the fairway and thegolfer takes a “regular” swing, then the golfer strives to make contactwith the ball on the lower portion of the club face, typically thelower, central portion of the club face. In such cases, the resultingball contact path along the striking face is substantially vertical andcentered on the striking face, when the club head is viewed in areference position relative to a ground plane, as defined below. For aflop shot, the golfer opens the club face to a large degree, which wouldresult in a different contact point location and angular orientation.Still other portions of the face may be used for other types of shots;for example, some golfers use the extreme outer toe portion of the face,with the toe pointed toward the playing surface, as the ball contactpoint for chip shots. The face may therefore be variably textured toenhance each of the different types of shots the golfer may perform.

The United States Golf Association (USGA) publishes and maintains theRules of Golf, which govern golf in the United States. Appendix II tothe USGA Rules provides several limitations for golf clubs. For example,currently, the width of a groove cannot exceed 0.035 inch, the depth ofa groove cannot exceed 0.020 inch, and the surface roughness within thearea where impact is intended must not exceed that of decorativesandblasting or of fine milling. The Royal and Ancient Golf Club of StAndrews, which is the governing authority for the rules of golf outsidethe United States, currently provides similar limitations to golf clubdesign.

Certain embodiments of the present invention, in one or more aspectsthereof, may advantageously comprise a golf club head that deliversimproved spin production, increased player confidence, and increasedplayability of the golf club by way of incorporating a plurality ofauxiliary grooves and/or texture elements into the striking face of thegolf club head.

In one or more embodiments, and as depicted by way of example in FIGS. 1through 1( a), a golf club head 100 comprises an iron-type golf clubhead. It is noted, however, that while the golf club head 100 isillustrated as an iron-type golf club head and is discussed with respectto conventional usage as a wedge, the golf club head 100 may be any ofan iron-type, putter-type, wood-type, hybrid-type, etc. golf club head.It is further noted that while the golf club head 100 is illustrated asbeing a right-handed golf club head, any reference to any position onthe golf club head 100 may be mirrored, and applied to a left-handedgolf club head.

Referring to FIG. 1, the golf club head 100 has a toe portion 101, aheel portion 103, a top portion 105, a bottom portion 107, and a hosel109 for receiving a shaft (not shown) that extends from golf club headproximate the heel portion 103. The hosel 109 has a hosel centerline 110that extends through the center point of a diameter cross-section of thehosel 109. The hosel 109 may also generally take any shape or positionwith respect to the golf club head 100. While the figures of thisapplication illustrate a golf club head 100 having a hosel 109, the golfclub head 100 may simply have a shaft reception location, e.g., anaperture, in lieu of the illustrated hosel 109 and be “hosel-less.”

The golf club head 100 also has a striking face 111 for striking a golfball. The striking face 111 has a plurality of scorelines 113 and aplurality of auxiliary grooves 115 interspersed between the scorelines113 and, in some embodiments, alternatively or additionally locatedoutside of the region generally occupied by the scorelines 113. Theplurality of scorelines 113 is provided on the striking face 111 toassist in imparting spin to a golf ball that contacts the striking face111. The scorelines may be machined, e.g. by milling, optionally byspin-milling, or may be forged, stamped, rolled, pressed, or cast. Inone or more embodiments, the plurality of auxiliary grooves 115 is adifferent type of surface treatment that extends between the scorelineextents. In some embodiments, the auxiliary grooves 115 vary inconcentration and/or orientation between the scorelines 113 whentraversing the striking face 111 from the toe portion 101 to the heelportion 103, and, additionally or alternatively, when traversing thestriking face 111 the top portion 105 to the bottom portion 107. Thestriking face generally lies in an imaginary striking face plane 112(see FIG. 1( a)). For example, the striking face 111 may be planar,textured, include scorelines, grooves, or have a slight curvature, e.g.,a bulge and/or roll of a high radius of curvature.

Conventionally, the orientation of the scorelines 113 is such that spinis maximized when the striking face 111 squarely impacts the golf ballwith respect to the reference position, or, in other words, the targetline, during a “regular” shot. However, when the orientation of thestriking face of a conventional golf club head that does not have anyauxiliary grooves deviates from the reference position, spin productionand playability are reduced.

The golf club head 100, as shown in FIG. 1, is in a reference position.As used herein, the term “reference position” refers to a position ofthe golf club head, e.g. club head 100, wherein the hosel centerline,e.g. hosel centerline 110, lies in an imaginary vertical hosel plane 104relative to a ground plane 102, and the scorelines 113 generally extendparallel to the ground plane 102. Any reference to the terms horizontalor vertical, unless otherwise indicated, is in reference to a golf clubhead that is in the reference position relative to a ground plane.

In some embodiments, as shown for example in FIG. 1, the auxiliarygrooves 115 vary in orientation and concentration across the strikingface 111 to increase spin performance, and player confidence, when thegolf club head 100 is oriented in a way that deviates from the referenceposition. The increase in spin production may be an overall increase ingenerated spin, and/or a reduction in an amount of spin lost between agolf club head 100 that does not include the auxiliary grooves 115 andone that does when each of these golf club heads 100 deviate from thereference position.

In one or more embodiments, the striking face 111 is polished, a nickellayer is applied, the striking face 111 is sandblasted, a second nickellayer is applied, and then the auxiliary grooves 115 are generated. Thiscombination of processing steps and materials produces anaesthetically-pleasing contrast between auxiliary groove 115 coloringand the striking face 111. In some embodiments, the final nickel-coatingprocess results in a dark, or black finish, further enhancing contrast.Further, such contrasts increase visibility of the auxiliary groovesand, in some embodiments, enhance a golfer's ability to align the clubhead with a golf ball.

Alternative or additional finishing processes may be applied to thestriking face 111 of the club head 100, preferably prior to productionof the auxiliary grooves 115. For example, the auxiliary grooves 115 maybe superimposed on a striking face 111 that is micro-milled,media-blasted, chemically-etched, stamped, forged, laser-peened,unpolished, has other metal layers, rusted, not sandblasted, etc.Further embodiments may incorporate micro-surface texturing incombination with a substrate that is cast, milled, machined, forged,case-hardened, plated, media-blasted, anodized, etc. Any variation inmaterials, formation, surface texturing, layup, etc. may have anaesthetic effect that creates an appealing contrast with the auxiliarygrooves 115, creates a moire pattern that aids in alignment, creates alarger-scale roughness profile, aids in water/debris channeling, and mayalter the performance and/or degree of feedback a player receives duringa golf shot.

The auxiliary grooves 115, in one or more embodiments, are texturedtroughs generated by a high temperature laser that locally softens thesurface of the striking face, creating a trough and generally roughenedarea surrounding the trough, otherwise known as “laser milling.” In someembodiments, such laser milling heat treats the striking face 111 in theregion to which it is applied, which results in a more durable surface,and tighter tolerances than mechanical milling/machining. Alternatively,or in addition to the laser milling, the auxiliary grooves 115 may begenerated by way of chemical etching, media blasting, milling,micro-milling, cross-milling, stamping, etc.

Laser milling is relatively non-invasive. In other words, it is tooshallow to negatively affect the structural integrity of striking face111. As such, there is no need to thicken the striking face. Further,the laser milling manner generating the auxiliary grooves 115 generallyavoids creation of stress concentrations, and is clean and precise. Thisprecision results in minimal waste and cleanup when compared to otherprocesses, such as machine-milling. Thus, laser milling iscost-effective. Further, laser milling may be applied withoutinterference with the structure of the scorelines 113 and, in somecases, does not require any significant after-polishing, thereby furthereffecting a high spin surface at a low cost with little machine wear.

The auxiliary grooves 115 change the color of the affected area of thestriking face 111 creating appealing contrast. This contrast increasesvisibility of scorelines 113, and increases the ability of the golfer toproperly align the golf club head 100 with a golf ball, therebyimproving a player's perception of the golf club head 100 and increasingthe player's confidence in his or her ability to make a successful golfshot.

Referring to FIG. 2, the club head 100 of FIG. 1 is shown in furtherdetail. The striking face 111 includes a plurality of scorelines 113 andauxiliary grooves 115 that are interspersed between the scorelines 113.As discussed above, in some embodiments, the auxiliary grooves extendoutward of the region generally occupied by the scorelines. Theplurality of scorelines 113 includes a heelwardmost extent 152, atoewardmost extent 154, an uppermost extent 156, and a lowermost extent158. The striking face 111 includes a face center 117. “Face center,” asreferred to herein, denotes a point on the striking face of a club head,halfway between the toewardmost extent 154 and the heelwardmost extent152 of the plurality of scorelines 113, horizontally, and halfwaybetween the uppermost extent 156 and the lowermost extent 158 of theplurality of scorelines 113, vertically.

Referring again to FIG. 2, the striking face 111 includes a continuousimaginary central region 119 that includes, and circumscribes, the facecenter 117. A peripheral region 121 is located entirely outward of thecentral region. In the central region 119, the auxiliary grooves 115 aregenerally horizontal. In the peripheral region 121, the auxiliarygrooves 115 are inclined. Other variable orientations of the auxiliarygrooves 115 may be realized such as a continuously-variable set ofauxiliary grooves, for example a curved set of auxiliary grooves 115that are similar in appearance to a milled face, discrete points (dotsor dashes), or small, spaced-apart shapes that follow a pattern thatgenerally varies in the heel-toe direction (see e.g. FIG. 5 discussedbelow). In various embodiments, the change in pattern is not gradual,but abrupt. Such variations in auxiliary groove 115 orientation resultsin specific performance advantages that will be discussed in more detailbelow.

As illustrated in FIGS. 1 and 2, proximate each of the heel and toeportions 103 and 101 of the golf club head 100, the auxiliary grooves115 follow discrete linear paths that are approximately 15 degrees fromhorizontal, measured in the striking face plane 112. In someembodiments, the auxiliary grooves 115 proximate the heelward andtoeward portions 103 and 101 follow discrete linear paths that areinclined 5-50 degrees from horizontal, measured in the striking faceplane 112, when the club head 100 is in the reference position.Specifically, the auxiliary grooves proximate the toe portion 101 areinclined 5-50 degrees from the horizontal, while the auxiliary groovesproximate the heel portion 103 are declined from the horizontal. Morepreferably, and in consideration of minimizing, or eliminating, thepotential for side spin to be imparted on the golf ball, the discretelinear paths are inclined between 5 and 20 degrees from horizontal,measured in the striking face plane, when the club head is in thereference position. The degree of incline or decline may be generallyuniform proximate the toe portion 101 and/or the heel portion 103, orvariable and, thus, based on the location on the striking face 111.

As shown in FIG. 2, the plurality of scorelines 113 is provided on thestriking face 111 to assist in imparting spin to a golf ball thatcontacts the striking face 111. A first scoreline 114 and a secondscoreline 116 of the plurality of scorelines 113 are illustrated.However, the first scoreline 114 and the second scoreline 116 may be anyadjacent pair of scorelines 113 on the striking face 111. Verticalcross-section A-A′ passes through the central region 119 of the strikingface, including the first scoreline 114 and the second scoreline 116. Insome embodiments, the vertical cross-section A-A′ passes through theface center 117. In alternative embodiments, the vertical cross-sectionA-A′ is laterally spaced from the face center 117. Verticalcross-section B-B′ is laterally spaced from the vertical cross-sectionA-A′ and passes through the peripheral portion 121 of the striking face111, including passing through the first scoreline 114 and the secondscoreline 116. As shown, vertical cross-section B-B′ is toeward of thevertical cross-section A-A′. However, in alternative embodiments, thevertical cross-section B-B′ is heelward of the vertical cross-sectionA-A′. Specifically, the vertical cross-section B-B′ is laterally spacedfrom the vertical cross-section A-A′ by a distance of 10 mm. However, inalternative embodiments, this distance is greater than, or less than, 10mm.

FIG. 2( a)(1) illustrates a toe-side view of vertical cross-section A-A′that passes through the central region 119 of FIG. 2 of the golf clubhead 100. The striking face 111 is generally coplanar with the strikingface plane 112. The striking face plane 112 defines a datum plane fromwhich depth, including maximum depth, of each of the scorelines 113 andthe auxiliary grooves 115 is measured. A highlighted region isillustrated by dashed lines for a detailed view that will be discussedin FIG. 2( a)(2).

Referring to FIG. 2( a)(2), which is a magnified view of the highlightedregion of FIG. 2( a)(1), the first scoreline 114 and the secondscoreline 116 are depicted. A lowermost point 118 of the first scoreline114 is illustrated as being a point at which a lower edge of the firstscoreline 114, the striking face plane 112 and the cross-section A-A′intersect. An uppermost point 120 of the second scoreline 116 isillustrated as being a point at which an upper edge of the secondscoreline 116, the striking face plane 112 and the cross-section A-A′intersect. As shown, the cross-sectional profiles of the scoreline 116may include a negatively-radiused region 160 and a positively-radiusedregion 162.

A first path 150 is formed along the striking face 111 by anintersection of the cross-section A-A′ and the striking face 111, andbetween the lowermost point 118 of the first scoreline 114 and theuppermost point 120 of the second scoreline 116. A distance X of thefirst path 150 is illustrated between the lowermost point 118 of thefirst scoreline 114 and the uppermost point 120 of the second scoreline116. Preferably, the distance between each pair of adjacent scorelines,in the cross-section A-A′, is substantially uniform. However, inalternative embodiments, the distance separating each pair of adjacentscorelines varies. A distance ω₁ is a width of a first of the auxiliarygrooves 115. Preferably, a width of each auxiliary groove in thecross-section A-A′ is substantially uniform. However, in alternativeembodiments, such widths vary. A distance ω₂ is a width of the secondscoreline 116. Preferably, the width of each scoreline in cross-sectionA-A′ is substantially uniform. However, in alternative embodiments, suchwidths vary.

A distance d₁ is a depth of one of the auxiliary grooves 115.Preferably, a depth of each of the auxiliary grooves shown in thecross-section A-A′ is substantially uniform, i.e. within the range oftypical tolerances associated with the material removal process used inits formation. However, in alternative embodiments, such depths vary. Adistance d₂ is a depth of the second scoreline 116. Preferably, a depthof each scoreline shown in the cross-section A-A′ is uniform. However,in alternative embodiments, such depths vary.

As used herein, the term “concentration” refers to the concentration ofauxiliary grooves over a specified length in a specified verticalcross-section, and is determined as a ratio of the total sum of widthsof all auxiliary grooves that traverse a specified segment of aspecified vertical cross-section to the overall length of the specifiedsegment of the specified vertical cross-section.

In the central region 119, e.g. in the cross-section A-A′, theconcentration of the plurality of auxiliary grooves 115 along the firstpath 150, in one or more embodiments, is no less than 0.12. However, inrecognition of the specific interaction between an elastomeric-type golfball and a metallic striking face, the concentration of the plurality ofauxiliary grooves 115 along the first path 150 is more preferablybetween 0.17 and 0.25. However, in alternative embodiments, specificallywhere it is intended to provide a striking face having selectable spincharacteristics dependent on the location of contact with a golf ball,the concentration may be less than 0.17 in areas intended to havereduced spin.

To further produce desired spin results, the average depth of theauxiliary grooves 115 in one embodiment is no greater than 15 microns.In another embodiment, the average depth of the auxiliary grooves 115 isno greater than 12 microns. In a further embodiment, the average depthof the auxiliary grooves 115 is between 6 microns and 12 microns.

Also, the average width of the auxiliary grooves 115 in some embodimentsis no greater than 1.0 mm. In another embodiment, the width of theauxiliary grooves 115 is no greater than 0.5 mm. In still anotherembodiment, the average width of the auxiliary grooves is no greaterthan 0.25 mm. In another embodiment, the average width of the auxiliarygrooves 115 is no greater than 0.20 min. In a further embodiment, theaverage width of the auxiliary grooves 115 is between 0.12 mm and 0.18mm.

A “frequency” of the plurality of auxiliary grooves, as used herein,refers to a number of all auxiliary grooves that traverse a specifiedpath of a specified vertical cross-section of a striking face of a clubhead. Over the first path 150, in the cross-section A-A′, a frequency ofthe auxiliary grooves 115 is preferably no less than 0.90 grooves/mm.More preferably, and in recognition of the specific dynamic interactionbetween an elastomeric-type golf ball and a metallic striking face, suchfrequency is no less than 1.00 grooves/mm. More preferably, suchfrequency is no less than 1.10 grooves/mm. In a further embodiment, suchfrequency is no more than 1.70 grooves/min. As discussed below,increasing or decreasing auxiliary groove frequency outside of thisrange has a deleterious effect on desired ball spin. The frequency ofthe auxiliary grooves 115 may be constant or variable between any twoadjacent scorelines of the plurality of scorelines 113 over the strikingface 111 and in a single cross-section, e.g. cross-section A-A′, orvariable between multiple cross-sections spaced apart laterally. Inother words, a first frequency between the same or different pair ofscorelines 113 may be the same or different from a second frequencybetween the same or different pair of scorelines 113, depending on thelocation of a cross-section that is taken of the golf club head 100.Generally, however, a change in frequency would have an advantageouseffect on the spin production in the case of alternative striking face111 orientations.

With respect to the number of auxiliary grooves 115 between any two ofthe plurality of scorelines 113, in one embodiment, the number ofauxiliary grooves 115 is no greater than five auxiliary grooves 115. Inanother embodiment, the number of auxiliary grooves 115 is no greaterthan four auxiliary grooves 115. In a further embodiment, the number ofauxiliary grooves 115 is no less than three auxiliary grooves 115.

The following tables 1-1 and 1-2 illustrate collected performance datarelating the frequency, concentration, and orientation of auxiliarygrooves 115 to spin production using robot testing. Table 1-1illustrates collected performance data comparing the auxiliary groovefrequency and concentration of a golf club head 100, in a specifiedcross-section of a central region 119 of the striking face 111, thelocation of which being constant for each test club head, to the spinrate of the golf ball after impact.

TABLE 1-1 Auxiliary Full shot Chip Shot Groove Auxiliary Using SrixonUsing Srixon Using Srixon Using Srixon Frequency Groove Z-URS golf SoftFeel golf Z-URS golf Soft Feel golf Average Spin (#/mm) Concentrationball (rpm) ball (rpm) ball (rpm) ball (rpm) (rpm) 0.993 0.149 9130 61264656 3094 5752 1.325 0.199 9133 6110 4876 4356 6119 1.656 0.248 93025458 4818 4067 5911 1.987 0.298 9449 3720 4987 3321 5369

FIG. 2( b)(1) illustrates a toe-side view of vertical cross-section B-B′that passes through the peripheral region 121 of FIG. 2 of the golf clubhead 100. The striking face plane 112 is illustrated and serves as adatum plane from which a depth of the scorelines 113 and the auxiliarygrooves 115 is measured. A highlighted region is illustrated by dashedlines for a detailed view that will be discussed in FIG. 2( b)(2).

Referring to FIG. 2( b)(2), which is a magnified view of the highlightedregion of FIG. 2( b)(1), the first scoreline 114 and the secondscoreline 116 are depicted. A lowermost point 118 of the first scoreline114 is illustrated as being a point at which a lower edge of the firstscoreline 114, the striking face plane 112 and the cross-section B-B′intersect. An uppermost point 120 of the second scoreline 116 isillustrated as being a point at which an upper edge of the secondscoreline 116, the striking face plane 112 and the cross-section B-B′intersect. A second path 123 is formed along the striking face 111 by anintersection of the cross-section B-B′ and the striking face 111, thesecond path 123 delimited by the lowermost point 118 of the firstscoreline 114 and the uppermost point 120 of the second scorelines 116.A distance λ₂ is illustrated between the lowermost point 118 of thefirst scoreline 114 and the uppermost point 120 of the second scoreline116. A distance ω₁ is a width of an auxiliary groove 115. A distance ω₂is a width of the second scoreline 116. A distance d₁ is a depth of theauxiliary grooves 115. A distance d₂ is a depth of the second scoreline116. While distances ω₂ and d₂ are illustrated with respect to thesecond scoreline 116, the first scoreline 114, or any other scoreline ofthe plurality of scorelines 113, may be of the same or a different valuefor its respective width and depth.

In one or more embodiments, the concentration, frequency, arid/or numberof auxiliary grooves 115 that occur between the first and secondscorelines 114, 116 along the first path 150 (i.e. in the cross-sectionA-A′) and the second path 123 (i.e. in the cross-section B-B′) aredifferent from one another. This variation in concentration causes thespin production to be different depending on the orientation of the golfclub head 100 when impacting a golf ball, as discussed above.Specifically, a concentration of the auxiliary grooves that traverse thecross-section B-B′ is preferably less than the concentration ofauxiliary grooves traversing the cross-section A-A′ in between the samefirst scoreline 114 and second scoreline 116. Specifically, suchconcentration is no greater than 0.18. More preferably, suchconcentration is between 0.05 and 0.18. Even more preferably, suchconcentration is between 0.12 and 0.16, most preferably substantiallyequal to 0.15.

Similarly, a frequency of all auxiliary grooves 115 traversing thesecond path 123 of the cross-section B-B′ is less than the frequency ofall auxiliary grooves 115 traversing the first path in the cross-sectionA-A′. Specifically, such frequency is preferably no greater than 1.30grooves/mm. More preferably, such frequency is between 0.50 grooves/mmand 1.15 grooves/mm. Even more preferably, such frequency is between0.85 grooves/mm and 1.05 grooves/mm, most preferably between 0.95grooves/mm and 1.05 grooves/mm. Similarly, the simple number ofauxiliary grooves that traverse the second path in the cross-sectionB-B′ is less than the number that traverse the first path ofcross-section A-A′, and in some embodiments less than four.

Table 1-2 includes performance data of a first golf club head having astriking face with a plurality of scorelines but absent any auxiliarygrooves, and a second golf club head identical to the first golf clubhead, but with auxiliary grooves following the pattern shown in FIGS. 1and 2. The “Change in spin rate . . . ” represents the measured changein backspin between a robot-tested shot with the club head square (i.e.a regular shot) and a robot-tested shot, at the same swing speed, withthe club head oriented with a substantially open face (i.e. a flopshot). Once the striking face 111 is opened on a golf club head 100having only scorelines 113, the amount of spin produced is 316 rpm lessthan that of the regular shot. However, for a golf club head 100 havingthe auxiliary grooves 115, in an angle-straight-angle orientation suchas that illustrated in FIG. 1, the amount of spin that is produced in aflop shot actually increases by 23 rpm. Therefore, there is animprovement in spin production performance during a flop shot between agolf club head 100 having only scorelines 113 and a golf club head 100having the auxiliary grooves 115 by 339 rpm.

TABLE 1-2 Change in spin rate between regular shot and flop shot (rpm)Standard club head having −316 scorelines only Standard club head having23 scorelines with auxiliary groove pattern of FIGS. 1 and 2

FIG. 3 illustrates the golf club head 100 of FIGS. 1 and 2, orientedsuch that the striking face plane 112 lies in the plane of the paper,and showing further detail. First, second, third and fourth imaginaryvertical planes 130, 132, 134, and 136 each pass through a portion ofthe striking face 111, and pass through a portion of the plurality ofscorelines 113. The first and second imaginary planes 130 and 132 arespaced by 10 mm from one another. The third and fourth imaginary planes134 and 136 are also spaced 10 mm from one another, both located toewardof both the first and second imaginary vertical planes 130 and 132. Ahighlighted region is also illustrated as a selection for viewing ingreater detail in FIG. 3( a).

FIG. 3( a) illustrates the highlighted portion of FIG. 3 such that theview is zoomed in on a portion of the striking face 111 with the firstscoreline 114, the second scoreline 116 and the auxiliary grooves 115 inview. First, second, third and fourth imaginary planes 130, 132, 134,and 136 are also illustrated. Highlighted selections for illustrating ingreater detail in FIGS. 3( b) and 3(c) are illustrated by respectivedashed lines.

FIG. 3( b) illustrates a magnified view of the portion highlighted inFIG. 3( a), showing how average concentration of the plurality ofauxiliary grooves 115, between the first and second scorelines 114 and116, and between the third and fourth imaginary vertical planes 134 and136, is to be measured. As used herein, “average concentration” of aplurality of auxiliary grooves, e.g. auxiliary grooves 115, refers to anaverage of a plurality of concentration measurements taken at 1 mmintervals between specified first and second imaginary vertical planes,and between specified first and second scorelines that are adjacent toeach other.

Accordingly, to determine the average concentration of the plurality ofauxiliary grooves 115 between the first scoreline 114 and the secondscoreline 116, and between the third imaginary vertical plane 134 andthe fourth imaginary vertical plane 136 (see FIG. 3( b)), concentrationmeasurements are taken at 1 mm intervals, such that 1₀ is taken alongthe fourth imaginary vertical plane 136 and each successiveconcentration measurement, 1₁, 1₂, . . . 1_(n), is taken at 1 mmintervals thereafter and until the third imaginary vertical plane 134 isreached.

An exemplary concentration measurement is taken at 1₅ and in thecross-section C-C′. FIG. 3( b)(1) is a toe-side view of thecross-section C-C′ illustrating the first scoreline 114 and the secondscoreline 116 having three auxiliary grooves, of the plurality ofauxiliary grooves 115, that traverse this particular cross-section. Thewidths of the traversing auxiliary grooves are illustrated by ω₃, ω₄ andω₅. The cross-section C-C′ is taken at a position where the distancebetween the first and second scorelines 114 and 116 is 1₅. Accordingly,a concentration of the auxiliary grooves 115 at cross-section C-C′ iscalculated as (ω₃+ω₄+ω₅)/1₅. The average concentration of auxiliarygrooves 115 in the region delimited by the first scorelines 114, thesecond scoreline 116, the first imaginary vertical plane 130, and thesecond imaginary vertical plane 132, is measured in similar manner, asshown in FIG. 3( c)(1), wherein an exemplary concentration measurement1₅ is taken at vertical cross-section D-D′.

The average concentration of the plurality of auxiliary grooves 115measured between the first scoreline 114 and the second scorelines 116,and between the third imaginary vertical plane 134 and the fourthimaginary vertical plane 136 (see FIG. 3( b)), is denoted by C₂. Theaverage concentration of the plurality of auxiliary grooves 115 measuredbetween the first scoreline 114 and the second scoreline 116, andbetween the first imaginary vertical plane 130 and the second imaginaryvertical plane 132 (see FIG. 3( c)), is denoted as C₁.

Preferably, C₁ is no less than 0.15. More preferably, C₁ is between 0.18and 0.25, most preferably equal to about 0.20. Preferably, C₂ is nogreater than 0.20. More preferably, C₂ is between 0.12 and 0.18, andmost preferably equal to about 0.15. Preferably, C₁ and C₂ are relatedin that C₁ is greater than C₂. More specifically, C₁ is preferablygreater than C₂ by at least 0.25, more preferably at least 0.35.Alternatively, or in addition, a ratio of the concentrations C₂/C₁ is nogreater than 0.85. In another embodiment, the ratio of concentrationsC₂/C₁ is no greater than 0.80. In still a further embodiment, the ratioC₂/C₁ is between 0.70 and 0.80. Alternatively, or in addition, the facecenter 117 of the striking face 111 is located within the regiondelimited by the first scoreline 114, the second scoreline 116, thefirst imaginary vertical plane 130, and the second imaginary verticalplane 132.

In FIG. 4, the golf club head 100 of FIG. 1 is shown illustratingfurther detail. As shown, the striking face plane 112 of the strikingface 111 is in the plane of the paper. The plurality of scorelines 113is located on the striking face 111. The plurality of scorelines 113includes a heelwardmost extent 152, a toewardmost extent 154, anuppermost extent 156, and a lowermost extent 158. A fifth imaginaryvertical plane 138 is perpendicular to the striking face plane 112 andpasses through the heelwardmost extent 152 of the plurality ofscorelines 113. A sixth imaginary vertical plane 140 is perpendicular tothe striking face plane 112 and passes through the toewardmost extent154 of the plurality of scorelines 113. A seventh imaginary verticalplane 142 is perpendicular to the striking face plane 112 and passesthrough the face center 117. The plurality of auxiliary grooves 115 arealso located on the striking face 111 and, in some embodiments, entirelyspaced from the plurality of scorelines 113. By entirely spacing theauxiliary grooves 115 from the scorelines 113, the auxiliary grooves 115will not interfere with the traction-enabling structure of thescorelines 113 nor will the auxiliary grooves 115 interfere with thestructural integrity of the scorelines. Specifically, such spacingprevents unintended generation of stress areas about the edges of thescorelines and/or unintended sharp regions that are susceptible to wear.In the alternative, such spacing reduces the need for further grindingand/or polishing about the edges of the scorelines 113, which may, inits own right, increase production costs, reduce design accuracy, anddeleteriously affect the traction-enabling benefit of the scorelines113.

The auxiliary grooves 115 define a first transition location 146 atwhich an auxiliary groove pattern transitions, e.g. from horizontal,spaced apart grooves to spaced apart grooves, proximate the heel portion103 of the club head 100, inclined relative to the ground plane. At asecond transition location 148, the auxiliary groove pattern againtransitions from horizontal spaced apart grooves to spaced apartgrooves, proximate the toe portion 101 of the club head 100, inclinedrelative to the ground plane. In some embodiments, either, or both, ofthe transition locations 146 and 148 lie at the intersection of thestriking face plane 112 and a vertical plane perpendicular to thestriking face plane 112. In alternative embodiments, either, or both, ofthe transition locations 146 and 148 lies along a linear path that isoblique relative to the direction of elongation of the scorelines 113.In alternative embodiments, either, or both, of the transition locations146 and 148 follow a generally curvilinear path along the striking faceplane 112.

An eighth imaginary vertical plane 144 is perpendicular to the strikingface plane 112 and coplanar with the transition location 146. A ninthimaginary vertical plane 145 is perpendicular to the striking face plane112 and coplanar with the transition location 148.

A width W of the plurality of scorelines 113 denotes the lateraldistance between the heelwardmost extent 152 and the toewardmost extent154 of the plurality of scorelines 113. The width W is preferably withinthe range of 35 mm to 65 mm, more preferably between 45 mm and 55 mm,and most preferably equal to about 50 mm. The fifth imaginary verticalplane 138 and the eighth imaginary vertical plane 144 are spaced apartby a distance L₅. The distance L₅ is preferably between 12 mm and 18 mm,more preferably equal to about 15 mm. The seventh imaginary verticalplane 142 and the eighth imaginary vertical plane 144 are spaced apartby a distance L₃. The distance L₃ is preferably between 6 mm and 14 mm,more preferably equal to about 10 mm. The seventh imaginary verticalplane 142 and the ninth imaginary vertical plane 145 are spaced apart bya distance L₂. The distance L₂ is preferably between 6 mm and 14 mm,more preferably equal to about 10 mm. The sixth imaginary vertical plane140 and the ninth imaginary vertical plane 145 are spaced apart by adistance L₄. The distance L₄ is preferably between 12 mm and 18 mm, morepreferably equal to about 15 mm.

In various embodiments, the seventh imaginary plane 142 is equidistantbetween the fifth imaginary plane 138 and the sixth imaginary plane 140.That is, L₅+L₃=L₄+L₂. Additionally, or alternatively, the eighth andninth imaginary planes 144 and 145 are spaced from the seventh imaginaryplane 142 by a distance D. In some embodiments, the distance D ispreferably between 0.10*W and 0.45*W.

In various embodiments, a central region is delimited by the eighthimaginary vertical plane 144 and the ninth imaginary vertical plane 145,a heel region is delimited by the fifth imaginary vertical plane 138 andthe eighth imaginary vertical plane 144, and a toe region is delimitedby the sixth imaginary vertical plane 140 and the ninth imaginaryvertical plane 145. In some embodiments, at least one of the auxiliarygrooves 115 follows a generally horizontal path, relative to the groundplane within the central region.

FIG. 5 illustrates a golf club head 200 that has a toe portion 201, aheel portion 203, a top portion 205, a bottom portion 207, and a hosel209 proximate the heel portion 203. The golf club head 200 also has astriking face 211 that has a plurality of scorelines 213 and a pluralityof texture elements, or auxiliary grooves, 215 interspersed between theplurality of scorelines 213. In this embodiment, the plurality oftexture elements 215 are a series of discrete regions of applied surfacetexturing. As shown, the texture elements take the form of a set of“dash-like” elements. However, in alternative embodiments, the textureelements may include any polygonal shape, including circle-shapedelements, rectangular-shaped elements, square-shaped elements,triangular-shaped elements, hexagonal-shaped elements, or anycombination thereof. Alternatively, or in addition, the texture elementsinclude irregularly-shaped elements. Preferably, the texture elements215 are formed by similar processes to those discussed with regard tothe auxiliary grooves of the embodiment shown in FIG. 1. Particularly,the texture elements preferably comprise heat-treat regions, formed by alaser milling operation. Further, the texture elements preferably are ofa depth similar to that of the auxiliary grooves 115 discussed withregard to the embodiments of FIGS. 1 through 4.

A first imaginary vertical plane 219 is illustrated as passing through acentral region of the striking face 211. A second imaginary verticalplane 221 is illustrated as passing through a toeward region of thestriking face 211. A third imaginary vertical plane 223 is illustratedas passing through a heelward region of the striking face 211. Thetexture elements 215 are generally horizontal in the central region. Thetexture elements 215 deviate from a horizontal orientation in each ofthe heelward and toeward regions, e.g. are inclined relative to a groundplane, in the striking face plane. Preferably, the texture elements 215are configured such that they include frequency values, concentrationvalues, and average concentration values that are similar to thosevalues discussed with regard to the embodiment of FIGS. 1 and 2, asdefined with regard to such embodiment, and at corresponding locationson the striking face.

Those skilled in the art will appreciate that while the presentinvention has been described in association with presently preferredaspects thereof, numerous changes, modifications and substitutions ofequivalents may be made therein without departing from the spirit andscope of this invention which is intended to be unlimited by theforegoing except as may appear in the following appended claims.

1. A golf club head comprising: a striking face having: a plurality ofscorelines including a first scoreline and a second scoreline adjacentto the first scoreline; and a plurality of auxiliary grooves each spacedfrom the plurality of scorelines; and wherein, when the club head is ina reference position: in a first imaginary vertical plane generallyperpendicular to the striking face and passing through the first andsecond scorelines: a first path is formed by a first intersectionbetween the first imaginary vertical plane and the striking face; andthe plurality of auxiliary grooves has a first concentration no lessthan 0.17 measured between the first scoreline and the second scoreline;and in a second imaginary vertical plane generally perpendicular to thestriking face and passing through the first and second scorelines, thesecond imaginary vertical plane being horizontally spaced from the firstimaginary plane: a second path is formed by a second intersectionbetween the second imaginary vertical plane and the striking face, andthe plurality of auxiliary grooves has a second concentration measuredbetween the first scoreline and the second scoreline, the secondconcentration being different from the first concentration.
 2. The golfclub head of claim 1, wherein each of the plurality of auxiliary grooveshas an average depth no greater than 15 microns.
 3. The golf club headof claim 1, wherein, in the first imaginary vertical plane, theplurality of auxiliary grooves has a frequency no less than 1.0grooves/mm measured between the first and second scorelines.
 4. The golfclub head of claim 3, wherein, in the first imaginary vertical plane,the plurality of auxiliary grooves has a frequency no less than 1.10grooves/mm measured between the first and second scorelines.
 5. The golfclub head of claim 1, wherein the first concentration is no greater than0.25.
 6. The golf club head of claim 1, wherein each of the plurality ofauxiliary grooves has an average width no greater than 1.0 mm.
 7. Thegolf club head of claim 6, wherein each of the plurality of auxiliarygrooves has an average width no greater than 0.5 mm.
 8. The golf clubhead of claim 1, wherein each of the plurality of auxiliary groovescomprises a heat-treated element.
 9. The golf club head of claim 1,wherein: the striking face comprises a textured surface region formed ofa texture selected from the group consisting of: a media-blastedtexture, a laser-peened texture, a milled texture, a chemically-etchedtexture, and a micro-milled texture; and the plurality of auxiliarygrooves is at least partially superimposed on the textured region.
 10. Agolf club head that when oriented in a reference position comprises: atop portion, and a bottom portion opposite the top portion; a heelportion, and a toe portion opposite the heel portion; a hosel extendingfrom the heel portion; and a striking face having: a plurality ofscorelines including a first scoreline and a second scoreline adjacentto the first scoreline; a plurality of texture elements, each spacedfrom the plurality of scorelines; a first and a second imaginaryvertical plane, each generally perpendicular to the striking face, eachpassing through the first and the second scorelines, and horizontallyspaced from each other by 10 mm; a third and a fourth imaginary verticalplane, each generally perpendicular to the striking face, each passingthrough the first and the second scorelines, each located toeward ofboth the first and the second imaginary vertical planes, andhorizontally spaced from each other by 10 mm; a first region delimitedby the first imaginary plane and the second imaginary plane, wherein, inthe first region, the plurality of texture elements has an averageconcentration, C₁, measured between the first and the second scorelines;and a second region delimited by the third imaginary plane and thefourth imaginary plane, wherein, in the second region, the plurality oftexture elements has an average concentration, C₂, measured between thefirst and the second scorelines, such that a ratio, C₂/C₁, is no greaterthan 0.85.
 11. The golf club head of claim 10, wherein each of theplurality of texture elements has an average depth no greater than 15microns.
 12. The golf club head of claim 10, wherein the ratio, C₂/C₁,is no greater than 0.80.
 13. The golf club head of claim 10, wherein theaverage concentration, C₁, is no less than 0.18.
 14. The golf club headof claim 13, wherein the average concentration, C₁, is between 0.18 and0.25.
 15. The golf club head of claim 10, wherein, in the first region,the plurality of texture elements comprises a frequency no less than 1.0elements/mm.
 16. The golf club head of claim 10, wherein each of theplurality of texture elements has an average width no greater than 1.0mm.
 17. The golf club head of claim 10, wherein each of the plurality oftexture elements comprises a heat-treated element.
 18. The golf clubhead of claim 10, wherein: the striking face comprises a texturedsurface region formed of a first texture selected from the groupconsisting of: a media-blasted texture, a laser-peened texture, a milledtexture, a chemically etched texture, and a micro-milled texture; andthe plurality of texture elements is formed of a second texturedifferent from the first texture, the plurality of texture elementsbeing at least partially superimposed on the textured surface region.19. A golf club head that when oriented in a reference position relativeto a ground plane comprises: a heel portion and a toe portion oppositethe heel portion; a hosel extending from the heel portion; and astriking face having a striking face plane; a face center; a centralregion including the face center; a peripheral region outward of thecentral region; a plurality of scorelines including at least a firstscoreline and a second scoreline adjacent the first scoreline, theplurality of scorelines extending into the central region and theperipheral region; and a plurality of auxiliary grooves at leastpartially interspersed within the plurality of scorelines, the pluralityof auxiliary grooves extending into the central region and theperipheral region, wherein: in the central region, one or more of theplurality of auxiliary grooves follows a generally horizontal pathrelative to the ground plane and the plurality of auxiliary grooves havean average concentration no less than 0.17 between the first scorelineand the second scoreline; and in the peripheral region, one or more ofthe plurality of auxiliary grooves follows a non-horizontal pathrelative to the ground plane.
 20. The golf club head of claim 19,wherein, in the peripheral region, the one or more of the plurality ofauxiliary grooves follows a linear inclined path relative to the groundplane.
 21. The golf club head of claim 20, wherein, in the peripheralregion, the one or more of the plurality of auxiliary grooves areinclined at an angle between 5 and 20 degrees relative to the groundplane, measured in the striking face plane.
 22. The golf club head ofclaim 19, wherein each of the plurality of auxiliary grooves has anaverage depth no greater than 15 microns.
 23. The golf club head ofclaim 19, wherein the average concentration is no greater than 0.25. 24.The golf club head of claim 19, wherein each of the plurality ofauxiliary grooves has an average width no greater than 1.0 mm.
 25. Thegolf club head of claim 19, wherein each of the plurality of auxiliarygrooves comprises a heat-treated element.
 26. A golf club head that whenoriented in a reference position relative to a ground plane comprises: aheel portion and a toe portion opposite the heel portion; a hoselextending from the heel portion; and a striking face having: a strikingface plane; a plurality of scorelines having a heelwardmost extent, atoewardmost extent, and a width, W, being the horizontal distancebetween the heelwardmost extent and the toewardmost extent, theplurality of scorelines including at least a first scoreline and asecond scoreline adjacent the first scoreline; a plurality of auxiliarygrooves at least partially interspersed within the plurality ofscorelines; a first imaginary vertical plane perpendicular to thestriking face plane and passing through the heelwardmost extent of theplurality of scorelines; a second imaginary vertical plane parallel tothe first imaginary vertical plane and passing through the toewardmostextent of the plurality of scorelines; a third imaginary vertical planeparallel to the first imaginary vertical plane and equidistant betweenthe first imaginary vertical plane and the second imaginary verticalplane; a fourth imaginary vertical plane parallel to the first imaginaryvertical plane and spaced from the third imaginary vertical plane towardthe heelwardmost extent by a distance, D, that is between 0.10*W and0.45*W; a fifth imaginary vertical plane parallel to the first imaginaryvertical plane and spaced from the third imaginary vertical plane towardthe toewardmost extent by the distance D; a central region delimited bythe fourth and the fifth imaginary vertical planes; a heel regiondelimited by the first and the fourth imaginary vertical planes; and atoe region delimited by the second and the fifth imaginary verticalplanes; wherein: in the central region, one or more of the plurality ofauxiliary grooves follows a generally horizontal path relative to theground plane and the plurality of auxiliary grooves have a concentrationno less than 0.17 measured between the first scorelines and the secondscoreline; and in at least one of the heel region and the toe region,one or more of the plurality of auxiliary grooves follows anon-horizontal path relative to the ground plane.
 27. A golf club headthat when oriented in a reference position relative to a ground planecomprises: a heel portion and a toe portion opposite the heel portion; ahosel extending from the heel portion; and a striking face having astriking face plane generally coplanar with the striking face; and aplurality of scorelines including at least a first scoreline and asecond scoreline adjacent the first scoreline, wherein: one or morefirst auxiliary grooves are interspersed between, and entirely spacedfrom, the plurality of scorelines, and follow an inclined path relativeto the ground plane at an angle between 5 and 50 degrees relative to thehorizontal, measured in the striking face plane; and one or more secondauxiliary grooves are interspersed between, and entirely spaced from,the plurality of scorelines, and follow a declined path relative to theground plane at an angle between 5 and 50 degrees relative to thehorizontal, measured in the striking face plane.